1. Field of the Invention
The present invention relates to the fixation of heavy metal contaminants present in soil using microwave radiation. More particularly, it relates to a method for fixing and rendering non-leachable the heavy metal contaminants present in soil contaminated with heavy metal containing oily wastes such as refinery waste oil streams.
2. Description of the Related Art
The treatment of metal- and oil-contaminated soils is the subject of much ongoing research. This is so because of the limits on the amount of hazardous wastes which can be discharged into the environment and the requirement that contaminated sites be cleaned up. Microwave radiation has been investigated as useful in remediation/clean-up activities, see for example "Microwave Treatment of Hazardous Wastes: Removal of Volatile and Semi-Volatile Organic Contaminants From Soil" Windgasse et al, Journal of Microwave Power and Electromagnetic Energy, Vol. 26, No. 1, 1992, pp. 23-32; "Microwave Treatment of Hazardous Wastes: Fixation of Chromium in Soil", Sedhom et al, Journal of Microwave Power and Electromagnetic Energy, Vol. 27, No. 2, 1992, pp. 81-86; "Microwave Treatment of Hazardous Wastes: Remediation of Soils Contaminated by Non-Volatile Organic Chemicals Like Dioxins", Zhu et al, Journal of Microwave Power and Electromagnetic Energy, Vol. 27, No. 1, 1992, pp. 54-61.
Numerous patents also address the use of microwave radiation energy in decontaminating soil contaminated with heavy metals and/or oily wastes. See U.S. Pat. No. 5,209,604; U.S. Pat. No. 5,193,934; U.S. Pat. No. 5,190,405; U.S. Pat. No. 5,169,263; U.S. Pat. No. 5,110,364; U.S. Pat. No. 5,076,727.